Hi, what edition and version are you using? I am using the Enterprise Edition and it uses VARCHAR2 in my Oracle DB.

Hello Anders, I'm using the Community Edition in version 7.0.18 of Joget. 
I follow this steps (http://ourexperienceatntg.blogspot.com/2017/04/joget-hibernate-issue-with-oracle.html) but it's still not working properly.

1.-I made a custom class equals to the example given by the URL.

2.-Made the jar and include the jar into the lib folder ($Joget-DX7\apache-tomcat-8.5.65\webapps\jw\WEB-INF\lib)

3.-I edit the hibernate.cfg.xml file in the $Joget-DX7\apache-tomcat-8.5.65\webapps\jw\WEB-INF\classes:

<property name="dialect">package.OracleCustomDialect</property>

It works creating the form the first time when I turn on the server but when I add a new field in the form it creates the field but it is stored as LONG values again.

Hi, I am unsure whether the Community edition is tested to work with Oracle. If you try using the Professional or Enterprise editions then it should work, like it does on mine.

I have solved the problem on my own.

Apparently the community version is missing the "dialect" folder in the path: Joget-DX7\apache-tomcat-8.5.65\webapps\jw\WEB-INF\classes\org\hibernate.
To obtain this file you have to install the Professional version and bring you the folder, then modify the Dialect in the hibernate.cfg.xml file.